<template>
    <div class="upload-file">
        <el-upload
            multiple
            :action="uploadFileUrl"
            :before-upload="handleBeforeUpload"
            :file-list="fileList"
            :data="data"
            :limit="limit"
            :on-error="handleUploadError"
            :on-exceed="handleExceed"
            :on-success="handleUploadSuccess"
            :show-file-list="false"
            :headers="headers"
            class="upload-file-uploader"
            ref="fileUpload"
            v-if="!disabled"
        >
            <!-- 上传按钮 -->
            <el-button type="primary">选取文件</el-button>
        </el-upload>
        <!-- 上传提示 -->
        <div class="el-upload__tip" v-if="showTip && !disabled">
            请上传
            <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b></template>
            <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b></template>
            的文件
        </div>
        <!-- 文件列表 -->
        <transition-group ref="uploadFileList" class="upload-file-list el-upload-list el-upload-list--text"
                          name="el-fade-in-linear" tag="ul">
            <li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content"
                v-for="(file, index) in fileList">
                <el-link :href="`${baseUrl}${file.url}`" underline="never" target="_blank">
                    <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
                </el-link>
                <div class="ele-upload-list__item-content-action">
                    <el-link underline="never" @click="handleDelete(index)" type="danger" v-if="!disabled">&nbsp;删除</el-link>
                </div>
            </li>
        </transition-group>
    </div>
</template>

<script setup>
import {getToken} from "@/utils/auth"
import Sortable from 'sortablejs'

const props = defineProps({
    modelValue: [String, Object, Array],
    // 上传接口地址
    action: {
        type: String,
        default: "/common/upload"
    },
    // 上传携带的参数
    data: {
        type: Object
    },
    // 数量限制
    limit: {
        type: Number,
        default: 5
    },
    // 大小限制(MB)
    fileSize: {
        type: Number,
        default: 5
    },
    // 文件类型, 例如['png', 'jpg', 'jpeg']
    fileType: {
        type: Array,
        default: () => ["doc", "docx", "xls", "xlsx", "ppt", "pptx", "txt", "pdf"]
    },
    // 是否显示提示
    isShowTip: {
        type: Boolean,
        default: true
    },
    // 禁用组件（仅查看文件）
    disabled: {
        type: Boolean,
        default: false
    },
    // 拖动排序
    drag: {
        type: Boolean,
        default: true
    }
})

const {proxy} = getCurrentInstance()
const emit = defineEmits(['before-upload'])
const number = ref(0)
const uploadList = ref([])
const baseUrl = import.meta.env.VITE_APP_BASE_API
const uploadFileUrl = ref(import.meta.env.VITE_APP_BASE_API + props.action) // 上传文件服务器地址
const headers = ref({Authorization: "Bearer " + getToken()})
const fileList = ref([])
const showTip = computed(
    () => props.isShowTip && (props.fileType || props.fileSize)
)

watch(() => props.modelValue, val => {
    if (val) {
        let temp = 1
        // 首先将值转为数组
        const list = Array.isArray(val) ? val : props.modelValue.split(',')
        // 然后将数组转为对象数组
        fileList.value = list.map(item => {
            if (typeof item === "string") {
                item = {name: item, url: item}
            }
            item.uid = item.uid || new Date().getTime() + temp++
            return item
        })
    } else {
        fileList.value = []
        return []
    }
}, {deep: true, immediate: true})

// 上传前校检格式和大小
function handleBeforeUpload(file) {
    // 校检文件类型
    if (props.fileType.length) {
        const fileName = file.name.split('.')
        const fileExt = fileName[fileName.length - 1]
        const isTypeOk = props.fileType.indexOf(fileExt) >= 0
        if (!isTypeOk) {
            proxy.$modal.msgError(`文件格式不正确，请上传${props.fileType.join("/")}格式文件!`)
            return false
        }
    }
    // 校检文件名是否包含特殊字符
    if (file.name.includes(',')) {
        proxy.$modal.msgError('文件名不正确，不能包含英文逗号!')
        return false
    }
    // 校检文件大小
    if (props.fileSize) {
        const isLt = file.size / 1024 / 1024 < props.fileSize
        if (!isLt) {
            proxy.$modal.msgError(`上传文件大小不能超过 ${props.fileSize} MB!`)
            return false
        }
    }
    proxy.$modal.loading("正在上传文件，请稍候...")
    number.value++
    emit('before-upload', file)
    return true
}

// 文件个数超出
function handleExceed() {
    proxy.$modal.msgError(`上传文件数量不能超过 ${props.limit} 个!`)
}

// 上传失败
function handleUploadError(err) {
    proxy.$modal.msgError("上传文件失败")
    proxy.$modal.closeLoading()
}

// 上传成功回调
function handleUploadSuccess(res, file) {
    if (res.code === 200) {
        uploadList.value.push({name: res.fileName, url: res.fileName})
        uploadedSuccessfully()
    } else {
        number.value--
        proxy.$modal.closeLoading()
        proxy.$modal.msgError(res.msg)
        proxy.$refs.fileUpload.handleRemove(file)
        uploadedSuccessfully()
    }
}

// 删除文件
function handleDelete(index) {
    fileList.value.splice(index, 1)
    emit("update:modelValue", listToString(fileList.value))
}

// 上传结束处理
function uploadedSuccessfully() {
    if (number.value > 0 && uploadList.value.length === number.value) {
        fileList.value = fileList.value.filter(f => f.url !== undefined).concat(uploadList.value)
        uploadList.value = []
        number.value = 0
        emit("update:modelValue", listToString(fileList.value))
        proxy.$modal.closeLoading()
    }
}

// 获取文件名称
function getFileName(name) {
    // 如果是url那么取最后的名字 如果不是直接返回
    if (name.lastIndexOf("/") > -1) {
        return name.slice(name.lastIndexOf("/") + 1)
    } else {
        return name
    }
}

// 对象转成指定字符串分隔
function listToString(list, separator) {
    let strs = ""
    separator = separator || ","
    for (let i in list) {
        if (list[i].url) {
            strs += list[i].url + separator
        }
    }
    return strs != '' ? strs.substr(0, strs.length - 1) : ''
}

// 初始化拖拽排序
onMounted(() => {
    if (props.drag && !props.disabled) {
        nextTick(() => {
            const element = proxy.$refs.uploadFileList?.$el || proxy.$refs.uploadFileList
            Sortable.create(element, {
                ghostClass: 'file-upload-darg',
                onEnd: (evt) => {
                    const movedItem = fileList.value.splice(evt.oldIndex, 1)[0]
                    fileList.value.splice(evt.newIndex, 0, movedItem)
                    emit('update:modelValue', listToString(fileList.value))
                }
            })
        })
    }
})
</script>
<style scoped lang="scss">
.el-upload__tip {
    font-size: 10px;
}

.file-upload-darg {
    opacity: 0.5;
    background: #c8ebfb;
}

.upload-file-uploader {
    margin-bottom: 5px;
}

.upload-file-list .el-upload-list__item {
    border: 1px solid #e4e7ed;
    line-height: 2;
    margin-bottom: 10px;
    position: relative;
    transition: none !important;
}

.upload-file-list .ele-upload-list__item-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: inherit;
}

.ele-upload-list__item-content-action .el-link {
    margin-right: 10px;
}
</style>
